public class test {
    public static void main(String[] args) {
        String onemoths="hello world";
        System.out.println(onemoths.indexOf("l"));
        System.out.println(onemoths.replaceAll("l","sb"));
        System.out.println(onemoths.replaceFirst("l","Sb"));
        System.out.println(onemoths.lastIndexOf("o",6));
        String s1=String.valueOf(99);
        String s2=String.valueOf(42.1);
        char []arr1={'a','b','c'};
        String s3=String.valueOf(arr1);
        System.out.println(s1);
        System.out.println(s2.toString());
        System.out.println(s3);
        String s4= String.valueOf(new Student("柳慧",18,"女"));
        System.out.println(s4);
        String s5="hello lxc";
        char []arr2=s5.toCharArray();
        for (int i=0;i<s5.length();i++){
            System.out.print(arr2[i]);
        }
        System.out.println();
        String s6=new String(arr2);
        System.out.println(s6);
        String s7=String.format("%d&%d&%d",2024,11,6);
        System.out.println(s7);
        String s8="abc+dsa+you+we";
        String []arr3=s8.split("\\+");
        for (String arr:arr3){
            System.out.println(arr);
        }
        System.out.println(s8.substring(2,5));

    }
}
